Electrical connector

ABSTRACT

An electrical connector comprising interengageable receptacle and plug members each including a plurality of contact elements which complete a series of electrical circuits through the connector when the members are interengaged. The plug and receptacle members are each formed by press fitting contacts into plated-through holes in an insulative substrate and then covering the protruding contacts with a layover insulative housing. The press fitted neck portion of each contact is reinforced by a longitudinally extending stiffening rib to permit the use of a contact material of relatively uniform thickness.

United States Patent 91 Ammon [451 Feb. 25, 1975 ELECTRICAL CONNECTOR[75] Inventor: John Preston Ammon, Dallas, Tex.

[73] Assignee: Elfab Corporation, Dallas, Tex.

[22] Filed: Sept. 4, 1973 [21] Appl. No.: 393,787

[52] US. Cl.... 339/17 M, 317/101 D, 339/176 MP,

339/184 M [51] Int. Cl H05k l/07, HOlr 13/64 [58] Field of Search339/17, 18, 75, 66, 65,

339/176,184,186, 217, 219, 220, 221; 317/101 D, 101 DH [56] ReferencesCited UNITED STATES PATENTS 2,699,534 l/l955 Hostermann 339/176 MP3,101,231 8/1963 Klostermann 339/176 MP 3,671,917 6/1972 Ammon et a1.339/17 L 3,721,941 3/1973 Wisser 339/17 CF Mattingly, Jr. et al.........339/186 M 1/1974 Kurtz et a1. 339/176 MP Primary Examiner-Roy D. FrazierAssistant ExaminerTerrell P. Lewis Attorney, Agent, or Firm-Clegg,Cantrell & Crisman [57] ABSTRACT An electrical connector comprisinginterengageable receptacle and plug members each including a pluralityof contact elements which complete a series of electrical circuitsthrough the connector when the members are interengaged. The plug andreceptacle members are each formed by press fitting contacts intoplated-through holes in an insulative substrate and then covering theprotruding contacts with a layover insulative housing. The press fittedneck portion of each contact is reinforced by a longitudinally extendingstiffening rib to permit the use of a contact material of relativelyuniform thickness.

13 Claims, 15 Drawing Figures PATENTED 3.868.162

sum3g3 FIG. I2

BACKGROUND OF THE INVENTION l. Field of the Invention The inventionrelates to an electrical connector and, more particularly, to anelectrical connector including substrate mounted plug and receptaclemembers which are engagable to complete a plurality of electricalcircuits through the connector.

2. History of the Prior Act One type of connector used ininterconnecting backpanels for printed circuit cards is that shown andclaimed in U.S. Pat. No. 3,671,917 to J. P. Ammon et al, assigned to theassignee of the present invention. Such connectors include rows ofcontact terminals press fitted into receiving apertures in a'substrate,generally known as a motherboard, and then covered by a layoverinsulative housing. The connector housings include a top opening forreceiving the edge ofa printed circuit card to be terminated, generallyknown as a daughter board.

Substrate mounted, card edge connectors, such as that disclosed in theAmmon et al patent, possess many advantages. For example, rows ofcontacts may be simultaneously press fitted into plated throughreceiving holes in the substrate for interconnection with printed wiringon the motherboard. This technique of manufacture, as taught in U.S.Pat. No. 3,676,926, produces rapid connector assembly and may also beused to produce a multi-layer motherboard in accordance with theteachings of U.S. Pat. No. 3,660,726. Further, substrate mounted cardedge connectors, such as that disclosed in the Ammon et al patent employa layover insulator which also contributes to speed of assembly and easeof repairability and preloading.

For certain applications, such as where it is inconvenicnt or impossibleto terminate one set of circuit paths along a card edge, the motherboardmounted edge connector is not practicable. In these situations it wouldbe desirable to use mating plug and receptacle members which,unfortunately, possess a number of disadvantages. Generally, in priorart plug and receptacle connectors each contact in both the plug memberand the receptacle member must be individually assembled into a housingand then individually wired to a circuit path. This consumes a greatdeal of assembly time and leads to a more expensive product.

The connector of the present invention combines the function of a plugand receptacle connector with the advantages of a substrate mounted,card edge type connector.

SUMMARY OF THE INVENTION The invention relates to an electricalconnector member having contact terminals inserted into a substrate andcovered by a layover insulative housing. More particularly, theinvention involves an electrical connector including interengagable plugand receptacle members comprising a pair of planar mounting substrateshaving a plurality of contact terminals mounted in each. A pair ofinterengagable, insulative plug and receptacle housings each comprise anouter shell having side walls open at the bottom to permit the shells tofit down over and substantially enclose the contact terminals and topopenings adapted for interengagement with one another. The plug housingis laid over the contact terminals mounted in one substrate while thereceptacle housing is laid over the contact terminals mounted in theother substrate. The contact terminals inone substrate are electricallycoupled to the contact terminals in the other substrate when the plugand receptacle members are interengaged.

BRIEF DESCRIPTION OF THE DRAWINGS For a more complete understanding ofthe present invention and for further objects and advantages thereof,reference may now be had to the following description taken inconjunction with the accompanying drawing, in which:

FIG. 1 is a perspective view of the interconnected plug and receptacleof the electrical connector of the present invention;

FIG. 2 is a vertical cross-section view taken about lines 2-2 of FIG. 1;

FIG. 3A is a front view of one embodiment of a strip supported contactterminal used in the invention;

FIG. 3B is a side view of the contact of FIG. 3A;

FIG. 3C is a cross-section view taken about the lines 3c-3c of FIG. 3A;

FIG. 4A is a front view of another embodiment of a strip supportedcontact terminal used in the invention;

FIG. 4B is a side view of the contact shown in FIG. 4A;

FIG. 5 is a top view of the receptacle member of the of the connector ofthe present invention;

FIG. 6 is a front view of the receptacle member shown in FIG. 5;

FIG. 7 is a vertical cross-section view taken about the lines 7-7 ofFIG. 5;

FIG. 8 is a top view of the plug member of the connector of the presentinvention;

FIG. 9 is a front view of the plug member shown in FIG. 8;

FIG. 10 is a vertical cross-section view taken about the lines 10-40 ofFIG. 8;

FIG. 11 is a side view of a receptacle member constructed in accordancewith the invention in interengagement with a cable connector plugmember; and

FIG. 12 is a side view of a plurality of motherboards interconnected bythe connector of the present inventron.

DETAILED DESCRIPTION Referring to FIG. 1, there is shown a plug andreceptacle electrical connector 10, constructed in accordance withtheinvention. The. connector 10 is shown interengaged with the plug member11 overlying and partially enclosing the receptacle member 12. The plugmember 11 is attached to and includes a first substrate 13 while thereceptacle member is fixed to a second parallel substrate 14. Both ofthe substrates l3 and 14 preferably comprise either single or plurallayer conventional printed circuit boards, having a plurality of rows ofholes 15 formed therein. A function of the connector 10 is to complete aplurality of circuit paths 16 located on the first substrate 13, throughthe connector 10 to a plurality of circuit paths (not shown) located onthe second substrate 14.

Referring now to FIG. 2, there is shown a crosssection view of theconnector 10 illustrating the manner in which the plug member 11 and thereceptacle member 12 are mechanically interfitted within one another andelectrically interengaged. Each of the substrates l3 and 14 maycomprise, in one embodiment,

a pair of conventional printed circuit boards 17 & 18.

The boards 17 and 18 are preferably formed of an insulative materialsuch as a glass filled epoxy resin (known 7 as G-lO Printed Circuitboard material) and may be either single or double sided, i.e., eachboard may have conductive pathways 16-(FIG. 1) formed on either one ofthe holes 15. The inside surface of each of the holes is preferablyplated with an inner layer of a conductive material such as copper, andan outer layer of tinlead material so that the upper and lower pads 21surrounding each hole 15 are joined by a continuous metal layer formingthe walls of a conventional platedthrough hole.

The adjacent boards 17 and 18 are separated by a thin layer ofinsulative material 22, such as MYLAR polyester film available from E.I. duPont de Nemours & Co. Each of the sheets 22 is drilled with holesto correspond with those in the board so that the platedthrough holes inthe pads 21 lie in axial alignment but are electrically isolated fromone another by the insulative sheets 22.

When the boards 17 and 18, of both the substrates l3 and 14, arearranged with the plated-through holes 15 in axial alignment, conductivemetal contact terminals 31 are press fitted into the holes 15 to be heldtight and motionless. If desired, the tin-lead material in the hole maybe heated and reflowed following the press fitting operation. Thecontacts 31 are preferably assembled into the boards 17 and 18 inaccordance with the techniques of US. Pat. No. 3,676,926 to formmulti-layer boards in accordance with US. Pat. No. 3,660,726, both ofwhich are assigned to the assignee of the present invention. I

Referring to FIGS. 3A and 38 there are shown, respectively, front andside views of a strip mounted contact terminal 31. The terminals arepreferably stamped from a single long thin strip of metal, suchasphosphor-bronze, and then finished by plating with a layer of nickel andan outer layer of gold, or some other acceptable contact plating. Thecontact terminals are joined to a common support strip 41 by a beveledreduced section 42.

Each of the contact terminals 31 comprises a connector portion 32 and aneck section 33 separated by a shoulder portion 34. The neck section 33is of such a width and thickness that when a contact 31 is press fittedinto a contact receiving hole 15, there is a tight frictional engagementbetween the neck 33 and the malleable inner walls of the hole 15 so thatthe contact is held rigid and motionless. The connector portion 32 ofthe contact terminal 31 is curved into a bowed configuration and isterminated at its upper end by a flange portion 35. A small detent 36 isimpressed into the face of the connector portion 32 to provide a snapaction engagement with other contact terminals. The contact terminal ofFIGS. 4A and 4B is identical to that of FIGS. 3A and 38 except that theformer also includes a shank portion 37 to permit additional wiringconnections by such techniques as wire wrapping.

As can be seen from reference to FIGS. 3A and 3B, the thickness of thecontact 31 is uniform and relatively thin throughout its entire length.To insure that the uniformly thin contact 31 flexes above the surface ofthe substrate, a central, axially extending ridge 38 is formed from apoint just above the shoulder portion 34 to a point just above thebottom of the neck section 33. The ridge 38 is formed generally alongthe region of the contact to be press fitted into a receiving hole. Asbest shown in FIG. 3C, the ridge 38 is formed by stamping a groove 39into the opposite face to plastically deform the metal. The centralridge 38 provides stiffness and rigidity to the present contact toensure that flexure thereof occurs above the surface of the mountingsubstrate.

FIGS. 5-7 show, respectively, top, side and end cross-sectional views ofa receptacle member 12 constructed in accordance with the invention.Referring first to FIG. 7, there is shown acorss-sectional view of thereceptacle member 12 illustrating a pair of contact terminals 31 pressfitted into the receiving holes 15 and substantially enclosed by aninsulative housing 51. The housing 51 is preferably formed of a moldableinsulative material such as nylon, plastic or a polycarbonate materialand includes an outer shell which is open at the bottom to allow theshell to fit down over and receive the contact terminals 31. The upperportion of the housing is partiall'yclosed by two U-shaped edge sections52 defining a top opening 53 for receiving a plug member to engage thecontact terminals 31. The housing 51 is preferably divided into aplurality of internal chambers 54 by transversely extending wallsections 55, each of which includes a central slot 56 for receiving aportion of a plug member. Each of the chambers 54 receives an opposedpair of contact terminals 31 when the insulative housing 51 is laid overthe terminal ends. An overhanginglip 57 is formed on the innermostportion of each of the U-shaped sections 52 to support the flangeportions 35 and preload the contacts As may be seen from the top view inFIG. 5, the rec'eptacle member 12 is polarity keyed by making one sidewall 58 of the insulator 51 somewhat longer than the other'side wall 59.When the receptacle member 12 is used with a plug member similarlykeyed, it is impossible to reverse the polarity of the mating contactsbecause the members will only fit together in one orientation.

FIGS. 8-10 show, respectively, top, side and end cross-sectional viewsof a plug member 11 constructed in accordance with the invention.Referring to FIG. 10, there is shown a cross-section of the plug member11, illustrating a pair of contact terminals 31 press fitted intoreceiving holes 15 in the substrate 13 and covered by an insulativehousing 61. The plug housing 61, like the receptacle housing 51, ispreferably formed of a moldable insulative material and includes anouter shell which is open at the bottom to allow the shell to fit downover and receive the contact terminals 31. The plug housing 61 comprisesa pair of spaced, parallel, upwardly extending side walls 62 and anupwardly extending central rib 63, parallel to and spaced between thewalls'62. The central rib 63 includes a transverse strip 64 extendingalong the top and forming a U- shaped edge 65 along each side, of thestrip 64. The inner portion of each of the U-shaped edges 65 isterminated by an overhanging lip section 66 which contacts and supportsthe flanged portion 35 of each contact terminal 31.

The inside bottom portion of the plug housing 61 is formed by a floor 67which is perforated by a plurality of spaced slots, each of which isdivided into two adjacent chambers 68 and 69 by the central rib 63. Eachof 31 of an opposed contact pair when the insulative plug housing 61 islaid over the terminal ends.

As can be seen from the top view in FIG. 8, the plug member 11 ispolarity keyed by making one side wall 71 of the insulator 61 somewhatlonger than the other sidewall 72. When the plug member 11 is used witha receptacle member similarly keyed, it is impossible to reverse thepolarity of the mating contacts because the members will only fittogether in one orientation. For example, the receptacle member 12 (ofFIG. 5) would only interengage the plug member 11 (of FIG. 8) with wall58 adjacent wall 71 and wall 59 adjacent wall 72.

Referring again to FIGS. 5, 6, and 7, the receptacle member 12 isassembled by separating the required number of contact terminals 31(FIGS. 3A & B or 4A & B) from a strip and inserting the shanks thereofinto receiving holes 15 in the substrate 14. Thecontact terminals 31 arethen press fitted into the holes to form two rows. The receiving holes15 into which the opposed contact terminal pairs are inserted are spacedfrom one another so that the bowed sections ofthe contactor positions 32of opposed terminal pairs are separated from one another a distanceslightly less than that between the mating plug member contacts to beinserted. The insulative housing 51 is then laid over the upper ends ofthe contact terminals to receive opposed pairs of contacts up into thechambers 54. When the housing 51 is initially placed over the contactterminals 31, it comes to rest with the ends ofthh overhanging lipportions 57 in contact with the ends of the flange portions 35, as canbe visualized from FIG. 7. The insulative housing 51 is placed in finalposition by caming the contact terminals 31 apart and pressing thehousing downwardly, as taught in US. Pat. No. 3,67l,9l7. In the finallyassembled receptacle member 12, the flanges 35 rest against the insideedges of the overhanging lip portions 57 and exert a preselected loadingforce against them.

Similarly, the plug member 11, of FIGS. 8, 9 and 10 is assembled byseparating a selected number of contact terminals 31 from a strip andinserting the shanks thereof into receiving holes in the substrate 13.The contacts 31 are then press fitted into the holes to form two rows ofopposed contact pairs. The insulative housing 61 is then laid over theupper ends of the contact terminals to receive opposed pairs of contactsup into the chambers 68 and 69. The housing 61 is placed in finalposition by caming the opposed rows of terminals toward one another andpressing the housing downwardly. In the finally assembled plug member11, the flanges 35 rest against the inside edges of the overhanging lipportions 66 and exert a preselected loading force against them.

When the plug and receptacle members 11 and 12, respectively, areinterengaged, as shown in FIG. 2, the central rib 63 extends down intothe top opening 53 while the body of the receptacle member 12 isreceived within the parallel walls 62 of the plug member 11. As the plugmember 11 is being inserted into the receptacle member 12, the contactorportions 32 of the respective terminals 31 engage one another. Thespacing of contacts is such that, during interengagement, both plug andreceptacle contacts are moved from their rest positions, i.e., abutingthe respective lip portions, and slid along the surface of one anotheruntil the opposed detents 36 have interlocked" each other, as shown inFIG. 2. This ensures a positive electrical connection between thecontactsof the plug member 11 and the contacts of the receptacle member12.

In other embodiments of the invention it will be understood that cableconnectors can be made by press fitting contacts into a substrate,laying an insulative housing over the contactor positions, severing thecontact supporting section of the substrate from the re- -mainder,attaching cable wires to the tails of the contacts and covering thecable wires and attachments with a cable hood.

It should be noted that either the plug member 11 or the receptaclemember 12 can be used with a mating cable connector. Referring to FIG.11, there is shown a receptacle member 81 mounted to a substrate 82 andhaving a plurality of outwardly extending contact tails 83. For example,the substrate 82 may comprise part of an interconnecting backpanel forelectronic components (not shown). The receptacle member 81 isinterengaged to a cable connector plug 84 which terminates a pluralityof wires 85 bound into a cable 86. The cable connector 84 may be of atype similar to the Blue Ribbon cable connector manufactured by theAmphenol Corporation. The wire/plug interconnections are covered by acable hood 87. Thus, it can be seen how electrical circuits on abackpanel can be interconnected with circuits in a cable by means of theconnector of the present invention.

Referring to FIG. 12, it can be seen how the plug and receptacle membersof the connector of the present invention may be used to directlyinterconnect and stack a plurality of circuit panels. Each panel 91 maycomprise either single or multi-layer interconnecting backpanels and mayhave both plug members 92 and receptacle members 93, mounted thereto. Byinterengaging the mating plug and receptacle members 92 and 93, theelectrical circuits on the panels 91 are easily interconnected.

Having described the invention in connection with certain specificembodiments thereof, it is to be understood that further modificationsmay now suggest themselves to those skilled in the art and it isintended to cover such modifications as fall within the scale of theappended claims.

What is claimed is:

1. An electrical connector including interengagable receptacle and plugmembers, comprising:

first and second substrates having aligned contact receiving hole arraystherein, each of said hole arrays lying along a linear path;

a plurality of contacts press fitted into the holes in each of saidsubstrates, said contacts each including a contactor portion resilientin a direction transverse to said linear paths lying along said holearrays;

an insulative receptacle housing placed down over to substantiallyenclose the press fitted contacts on the first substrate, saidreceptacle housing having bottom openings of sufficient size to receivethe contactor portions of said contacts and a top opening to receive aplug member, said receptacle housing having substantially planar innerwall surfaces extending parallel to said linear paths lying along saidhole arrays and spaced from any engagement with the rear portions ofsaid receptacle contacts; and

an insulative plug housing placed down over to substantially enclose thepress fitted contacts on the second substrate, said plug housing havingbottom openings of sufficient size to receive the contactor portions ofsaid contacts, and a top opening surrounding a central rib, said centralrib having substantially planar inner wall surfaces extending parallelto said linear paths lying along said hole arrays and spaced from anyengagement with the rear portions of said plug contacts, said plug andreceptacle members being interengagable by inserting the central rib ofsaid plug into the top opening of said receptacle to receive thereceptacle housing into the top opening of said plug housing and bringthe respective plug and receptacle contacts into generally parallel,facing electrical engagement along a line parallel to said linear holearrays and spaced from the inner wall surfaces of both said plug andsaid receptacle housings with the forces of engagement between contactsbeing in a direction perpendicular to said line of engagement.

2. An electrical connector including interengagable receptacle and plugmembers so set forth in claim 1 wherein: i

the contacts are press fitted into the first substrate in two parallelrows along saidlinear paths with the contactor portions of adjacentreceptacle contacts in different rows, forming contact pairs, facingtoward one another and spaced from the inner wall surfaces of saidreceptacle housing; the contacts are press fitted into the secondsubstrate in two parallel rows along said linear paths with thecontactor portions of adjacent plug contacts in different rows formingcontact pairs, facing away from one another andbeing separated by thecentral rib of said plug housing and spaced from the inner wall surfacesof said central rib; and the contactor portions of said plug andreceptacle contacts electrically connect one another when said plug andreceptacle members are interengaged along a line parallel to said linearpaths with forces of engagement being perpendicular to said paths. 3. Anelectrical connector including interengagable receptacle and plugmembers as set forth in claim 2 wherein:

each of said receptacle contacts are preloaded to exert a force towardthe adjacent contacts in said pairs; and each of said plug contacts arepreloaded to exert a force away from the adjacent contacts in saidpairs. 4. An electrical connector including interengagable receptacleand plug members as set forth in claim 3 wherein:

said contacts each include a flange portion at the upper end thereof;said receptacle housing includes a pair of lip portions parallel to saidlinear paths lying along said hole arrays and spaced from one another onopposite sides of the top opening, said contact flanges engaging saidlip portions to preload said receptacle contacts with forces acting in adirection perpendicular to said linear paths; and said plug housingincluding a pair of lip portions extending on opposite sides of saidcentral rib to engage the contact flanges and preload said plug contactswith forces acting in a direction perpendicular to said linear paths.

5. An electrical connector including interengagable receptacle and plugmembers as set forth in claim 1 wherein:

said contacts each include a central, axially extending stiffening ridgeformed in the contact region press fitted into the holes in thesubstrates.

6. An electrical connector including interengagable receptacle and plugmembers as set forth in claim 5 wherein:

said contacts are of generally uniform thinness and each also include agroove formedfin the opposite surface thereof from said ridge.

7. An electrical connector including interengagable receptacle and plugmembers comprising:

a pair of planar mounting substrates;

a plurality of contact terminals mounted in each of said substrates incontact arrays wherein said contacts mounted in each substrate lie alonglinear paths;

' a pair of interengagable, insulative plug and receptacle housings eachcomprising an outer shell having side walls open at the bottom to permitsaid shells to fit down over and substantially enclose said' contactterminals above said substrates and top openings adapted forinterengagement with one an- I other the inner surfaces of said outershells being substantially planar and extending parallel to said linearpaths spaced from said contacts, said plug housing being fitted downover contact terminals mounted in one substrate andsaid receptaclehousing being fitted down over contact terminals mounted in the othersubstrate, contact terminals in one substrate being electrically coupledto aligned contact terminals in the other substrate along a line ofengagement parallel to said-linear paths by forces perpendicular to saidlinear paths when the plug and receptacle members are interengaged.

8. An electrical connector including interengagable receptacle and plugmembers as set forth in claim 7 wherein:

each of said contact terminals includes a flange portion at one endthereof, a neck section at the opposite end thereof mounted in saidsubstrate and a contactor portion inbetween; and

said outer shells including lip portions adjacent the top openings whichengage the flange portions of said contact terminals to flex each ofsaid contacts above the point of engagement of said contacts in saidsubstrate and uniformly preload said contacts with forces acting in adirection perpendicular to said linear paths.

9. An electrical connector including interengagable receptacle and plugmembers as set forth in claim 8 wherein:

each of said contact terminals are of generally uniform thinness andalso include a central, axially extending stiffening rib formed in onesurface thereof in the region of the neck section to ensure said contactterminals flex above the surfaces of said subtrates.

10. An electrical connector including interengagable receptacle and plugmembers as set forth in claim 7 wherein:

said contact terminals are mounted in said substrates in opposed contactpairs; and

terengagement with a cable connector, comprising:

a planar substrate having aligned contact receiving holes therein; aplurality of contacts press fitted into the holes in saidsubstrate, saidcontacts each being resilient in a direction transverse to said alignedholes; and

an insulative housing having bottom openings of sufficient size toreceive said contacts and a top opening to receive a cable connector,said housing being placed down over said press fitted contacts tosubstantially enclose said contacts and to receive a cable connector inthe top opening with the contacts of said cable connector in conductiveengagement with the contacts of said connector member;

a cable including a plurality of wires, each attached respectively toone of said press fitted contacts on the opposite side of said substratefrom said insulative housing; and

a cable hood attached to said substrate and enclosing said wires andtheir respective points of attachment.

12. A plurality of stacked, interconnected printed circuit substratearrays comprising:

a plurality of insulative substrates arranged in parallel planes andspaced from one another a preselected distance;

a plurality of longitudinally spaced contact receiving hole arrays ineach of said substrates, each of said holes being plated and inelectrical connection with circuitry on said substrate, said hole arrayslying along linear paths of predetermined length, each path beingopposite to a path on a parallel adjacent substrate; plurality ofcontacts press fitted into the holes in each of said substrates, saidcontacts each including a contactor portion resilient in a directiontransverse to said linear paths lying along said hole arrays, thecontacts on one substrate extending toward an adjacent substrate;

an insulative receptacle housing placed down over to substantiallyenclose the press fitted contacts on a first one ofsaid plurality ofsubstrates and extending toward said spaced parallel adjacent substrate,said receptacle housing having bottom openings of sufficient size toreceive the contactor portions of said contacts and a top opening toreceive an interconnecting plug member, said receptacle housing havingsubstantially planar inner wall surfaces extending parallel to saidlinear paths lying along said hole arrays and spaced from any engagementwith the rear portions of said receptacle contacts;

aninsulative plug housing placed down over to substantially enclose thepress fitted contacts on a second one of said plurality of substratesand extending toward said spaced, parallel adjacent substrate and inalignment with said receptacle housing, said plug housing having bottomopenings of sufficient size to receive the contactor portions of saidcontacts, and a top opening surrounding a central rib, said central ribhaving substantially planar inner wall surfaces extending parallel tosaid linear paths lying along said hole arrays and spaced from anyengagement with the rear portions of said plug contacts, said plug andreceptacle members being interengagable by inserting the central rib ofsaid plug into the top opening of said receptacle to receive thereceptacle housing into the top opening of said plug housing andelectrically connect circuitry on said adjacent substrates by bringingthe respective plug and receptacle contacts into generally parallel,facing electrical engagement along a line parallel to said linear holearrays and spaced from the inner wall surfaces of both vsaid plug andsaid receptacle housings with the forces of engagement between contactsbeing in a direction perpendicular to said line of engagement.

13. A plurality of stacked, interconnected printed circuit substrates asset forth in claim 12, wherein:

said substrate arrays comprise at least three substrates;

each substrate includes a housing enclosed array of contacts projectingtoward the surface of a parallel adjacent substrate; and

each housing and contact array is interconnected with a mating housingon the adjacent substrate to electrically couple each of the substratesin said stack.

1. An electrical connector including interengagable receptacle and plugmembers, comprising: first and second substrates having aligned contactreceiving hole arrays therein, each of said hole arrays lying along alinear path; a plurality of contacts press fitted into the holes in eachof said substrates, said contacts each including a contactor portionresilient in a direction transverse to said linear paths lying alongsaid hole arrays; an insulative receptacle housing placed down over tosubstantially enclose the press fitted contacts on the first substrate,said receptacle housing having bottom openings of sufficient size toreceive the contactor portions of said contacts and a top opening toreceive a plug member, said receptacle housing having substantiallyplanar inner wall surfaces extending parallel to said linear paths lyingalong said hole arrays and spaced from any engagement with the rearportions of said receptacle contacts; and an insulative plug housingplaced down over to substantially enclose the press fitted contacts onthe second substrate, said plug housing having bottom openings ofsufficient size to receive the contactor portions of said contacts, anda top opening surrounding a central rib, said central rib havingsubstantially planar inner wall surfaces extending parallel to saidlinear paths lying along said hole arrays and spaced from any engagementwith the rear portions of said plug contacts, said plug and receptaclemembers being interengagable by inserting the central rib of said pluginto the top opening of said receptacle to receive the receptaclehousing into the top opening of said plug housing and bring therespective plug and receptacle contacts into generally parallel, facingelectrical engagement along a line parallel to said linear hole arraysand spaced from the inner wall surfaces of both said plug and saidreceptacle housings with the forces of engagement between contacts beingin a direction perpendicular to said line of engagement.
 2. Anelectrical connector including interengagable receptacle and plugmembers so set forth in claim 1 wherein: the contacts are press fittedinto the first substrate in two parallel rows along said linear pathswith the contactor portions of adjacent receptacle contacts in differentrows, forming contact pairs, facing toward one another and spaced fromthe inner wall surfaces of said receptacle housing; the contacts arepress fitted into the second substrate in two parallel rows along saidlinear paths with the contactor portions of adjacent plug contacts indifferent rows forming contact pairs, facing away from one another andbeing separated by the central rib of said plug housing and spaced fromthe inner wall surfaces of said central rib; and the contactor portionsof said plug and receptacle contacts electrically connect one anotherwhen said plug and receptacle members are interengaged along a lineparallel to said linear paths with forces of engagement beingperpendicular to said paths.
 3. An electrical connector includinginterengagable receptacle and plug members as set forth in claim 2wherein: each of said receptacle contacts are preloaded to exert a forcetoward the adjacent contacts in said pairs; and each of said plugcontacts are preloaded to exert a force away from the adjacent contactsin said pairs.
 4. An electrical connector including interengagablereceptacle and plug members as set forth in claim 3 wherein: saidcontacts each include a flange portion at the upper end thereof; saidreceptacle housing includes a pair of lip portions parallel to saidlinear paths lying along said hole arrays and spaced from one another onopposite sides of the top opening, said contact flanges engaging saidlip portions to preload said receptacle contacts with forces acting in adirection perpendicular to said linear paths; and said plug housingincluding a pair of lip portions extending on opposite sides of saidcentral rib to engage the contact flanges and preload said plug contactswith forces acting in a direction perpendicular to said linear paths. 5.An electrical connector including interengagable receptacle and plugmembers as set forth in claim 1 wherein: said contacts each include acentral, axially extending stiffening ridge formed in the contact regionpress fitted into the holes in the substrates.
 6. An electricalconnector including interengagable receptacle and plug members as setforth in claim 5 wherein: said contacts are of generally uniformthinness and each also include a groove formed in the opposite surfacethereof from said ridge.
 7. An electrical connector includinginterengagable receptacle and plug members comprising: a pair of planarmounting substrates; a plurality of contact terminals mounted in each ofsaid substrates in contact arrays wherein said contacts mounted in eachsubstrate lie along linear paths; a pair of interengagable, insulativeplug and receptacle housings each comprising an outer shell having sidewalls open at the bottom to permit said shells to fit down over andsubstantially enclose said contact terminals above said substrates andtop openings adapted for interengagement with one another the innersurfaces of said outer shells being substantially planar and extendingparallel to said linear paths spaced from said contacts, said plughousing being fitted down over contact terminals mounted in onesubstrate and said receptacle housing being fitted down over contactterminals mounted in the other substrate, contact terminals in onesubstrate being electrically coupled to aligned contact terminals in theother substrate along a line of engagement parallel to said linear pathsby forces perpendicular to said linear paths when the plug andreceptacle members are interengaged.
 8. An electrical connectorincluding interengagable receptacle and plug members as set forth inclaim 7 wherein: each of said contact terminals includes a flangeportion at one end thereof, a neck section at the opposite end thereofmounted in said substrate and a contactor portion in between; and saidouter shells including lip portions adjacent the top openings whichengage the flange portions of said contact terminals to flex each ofsaid contacts above the point of engagement of said contacts in saidsubstrate and uniformly preload said contacts with forces acting in adirection perpendicular to said linear paths.
 9. An electrical connectorincluding interengagable receptacle and plug members as set forth inclaim 8 wherein: each of said contact terminals are of generally uniformthinness and also include a central, axially extending stiffening ribformed in one surface thereof in the region of the neck section toensure said contact terminals flex above the surfaces of said subtrates.10. An electrical connector including interengagable receptacle and plugmembers as set forth in claim 7 wherein: said contact terminals aremounted in said substrates in opposed contact pairs; and said insulativehousings each include wall surfaces spaced from said contacts andextending perpendicular to said linear paths to separate adjacent onesof said contact pairs.
 11. An electrical connector member adapted forinterengagement with a cable connector, comprising: a planar substratehaving aligned contact receiving holes therein; a plurality of contactspress fitted into the holes in said substrate, said contacts each beingresilient in a direction transverse to said aligned holEs; and aninsulative housing having bottom openings of sufficient size to receivesaid contacts and a top opening to receive a cable connector, saidhousing being placed down over said press fitted contacts tosubstantially enclose said contacts and to receive a cable connector inthe top opening with the contacts of said cable connector in conductiveengagement with the contacts of said connector member; a cable includinga plurality of wires, each attached respectively to one of said pressfitted contacts on the opposite side of said substrate from saidinsulative housing; and a cable hood attached to said substrate andenclosing said wires and their respective points of attachment.
 12. Aplurality of stacked, interconnected printed circuit substrate arrayscomprising: a plurality of insulative substrates arranged in parallelplanes and spaced from one another a preselected distance; a pluralityof longitudinally spaced contact receiving hole arrays in each of saidsubstrates, each of said holes being plated and in electrical connectionwith circuitry on said substrate, said hole arrays lying along linearpaths of predetermined length, each path being opposite to a path on aparallel adjacent substrate; a plurality of contacts press fitted intothe holes in each of said substrates, said contacts each including acontactor portion resilient in a direction transverse to said linearpaths lying along said hole arrays, the contacts on one substrateextending toward an adjacent substrate; an insulative receptacle housingplaced down over to substantially enclose the press fitted contacts on afirst one of said plurality of substrates and extending toward saidspaced parallel adjacent substrate, said receptacle housing havingbottom openings of sufficient size to receive the contactor portions ofsaid contacts and a top opening to receive an interconnecting plugmember, said receptacle housing having substantially planar inner wallsurfaces extending parallel to said linear paths lying along said holearrays and spaced from any engagement with the rear portions of saidreceptacle contacts; an insulative plug housing placed down over tosubstantially enclose the press fitted contacts on a second one of saidplurality of substrates and extending toward said spaced, paralleladjacent substrate and in alignment with said receptacle housing, saidplug housing having bottom openings of sufficient size to receive thecontactor portions of said contacts, and a top opening surrounding acentral rib, said central rib having substantially planar inner wallsurfaces extending parallel to said linear paths lying along said holearrays and spaced from any engagement with the rear portions of saidplug contacts, said plug and receptacle members being interengagable byinserting the central rib of said plug into the top opening of saidreceptacle to receive the receptacle housing into the top opening ofsaid plug housing and electrically connect circuitry on said adjacentsubstrates by bringing the respective plug and receptacle contacts intogenerally parallel, facing electrical engagement along a line parallelto said linear hole arrays and spaced from the inner wall surfaces ofboth said plug and said receptacle housings with the forces ofengagement between contacts being in a direction perpendicular to saidline of engagement.
 13. A plurality of stacked, interconnected printedcircuit substrates as set forth in claim 12, wherein: said substratearrays comprise at least three substrates; each substrate includes ahousing enclosed array of contacts projecting toward the surface of aparallel adjacent substrate; and each housing and contact array isinterconnected with a mating housing on the adjacent substrate toelectrically couple each of the substrates in said stack.